paisley, I know it's easy to say but please don't worry about breast cysts or other benign lumps, they are very common. Like you, I have breast ultrasound (every year in my case) and they show up all sorts of things that are not detected on mammograms and mine showed up a cyst. If they thought there was any chance of it being something sinister, you would have to have it removed immediately and sent for a biopsy. Someone I know in Spain had to have this procedure and she was told if she refused, her health insurance would not cover her for anything breast related in the future. They don't take any chances. I should add that breast cysts are nothing to do with cancer, they are sacs of liquid that never turn into cancer. If someone has a lump that turns into cancer then it was not a cyst. I have spoken to various breast specialists about this at length and it does not preclude you from taking HRT.
Not all gynaecologists are pro-HRT so don't let it put you off starting the Lenzetto which I have to say is brilliant. You were told not to take HRT until you have to and if that time is now then why not start?